Communication systems may support wireless and wireline communications between wireless and/or wireline communication devices. Each type of communication system may be constructed/configured to operate in accordance with one or more communication standards. For instance, wireless communication systems may operate in accordance with one or more standards including, but not limited to, Radio Frequency Identification (RFID), Institute of Electrical and Electronic Engineers (IEEE) 802.11, Bluetooth®, advanced mobile phone services (AMPS), digital AMPS, global system for mobile communications (GSM), code division multiple access (CDMA), local multi-point distribution systems (LMDS), multi-channel-multi-point distribution systems (MMDS), and/or variations thereof.
A wireless communication device, such as a cellular telephone, two-way radio, personal digital assistant (PDA), personal computer (PC), laptop computer, home entertainment equipment, radio frequency identification (RFID) reader, RFID tag, etc. may communicate directly or indirectly with other wireless communication devices. For direct communications (also known as point-to-point communications), the participating wireless communication devices may tune their receivers and transmitters to the same channel(s) (e.g., one of the plurality of RF carriers of a wireless communication system or a particular RF frequency for some systems) and communicate over that channel(s). For indirect wireless communications, a wireless communication device may communicate directly with an associated BS (e.g., for cellular services) and/or an associated access point (AP) (e.g., for an in-home or in-building wireless network) via an assigned channel. The BS/AP may then relay the communication to another wireless communication device either directly or through additional base stations/access points, etc. To complete a communication connection between the wireless communication devices, the associated BSs and/or associated APs may communicate with each other directly, via a system controller, the public switch telephone network, the Internet, and/or some other wide area network.
To participate in wireless communications, each wireless communication device may include a built-in radio transceiver (i.e., receiver and transmitter), or may be coupled to an associated radio transceiver (e.g., a station for in-home and/or in-building wireless communication networks, RF modem, etc.). In most applications, radio transceivers are implemented in one or more integrated circuits (ICs), which can be inter-coupled via traces on a printed circuit board (PCB).
A transmitter aspect of the radio transceiver can include a data modulation stage, one or more intermediate frequency (IF) stages, and a power amplifier (PA). The data modulation stage can be configured to convert raw data into baseband signals in accordance with a particular wireless communication standard. The one or more intermediate frequency stages can be configured to mix the baseband signals with one or more local oscillations to produce RF signals. The PA can be configured to amplify the RF signals prior to transmission via an antenna.
A receiver aspect of the radio transceiver can be coupled to the antenna through an antenna interface and can include a low noise amplifier (LNA), one or more intermediate frequency stages, a filtering stage, and a data recovery stage. The LNA can be configured to receive inbound RF signals via the antenna and amplify them. The one or more IF stages can be configured to mix the amplified RF signals with one or more local oscillations to convert the amplified RF signal into baseband signals or IF signals. The filtering stage can be configured to filter the baseband signals or the IF signals to attenuate unwanted, out-of-band signals to produce filtered signals. The data recovery stage can then recover raw data from the filtered signals in accordance with the particular wireless communication standard.